Answer:
The poet refers to man's final stage as “second childishness and mere oblivion” since the person becomes old and forgetful during this time. He loses all of his senses and other abilities. He behaves and acts like a child in his moods and hobbies. It is the age of childish oblivion.
What is the fourth stage in the poem all the world's a stage?
Seeking the bubble reputation”.
According to the poet, every man has seven stages during his life time. These lines describe the fourth stage of a man's attitude. Explanation: In his fourth stage, as a soldier, a man is very jealous in his honor. He is ready to fight with his enemy.